1 files changed, 10 insertions, 1 deletions

diff --git a/plugins/check_smtp.c b/plugins/check_smtp.c
index d1c24666..986c3e18 100644
--- a/plugins/check_smtp.c
+++ b/plugins/check_smtp.c
@@ -480,6 +480,8 @@ process_arguments (int argc, char **argv)
         int c;
         char* temp;
 
+        bool implicit_tls = false;
+
         enum {
           SNI_OPTION
         };
@@ -650,6 +652,8 @@ process_arguments (int argc, char **argv)
 #else
                         usage (_("SSL support not available - install OpenSSL and recompile"));
 #endif
+                        implicit_tls = true;
+                        // fallthrough
                 case 's':
                 /* ssl */
                         use_ssl = true;
@@ -717,7 +721,12 @@ process_arguments (int argc, char **argv)
                 from_arg = strdup(" ");
 
         if (use_starttls && use_ssl) {
-                usage4 (_("Set either -s/--ssl/--tls or -S/--starttls"));
+                if (implicit_tls) {
+                        use_ssl = false;
+                        server_port = SMTP_PORT;
+                } else {
+                        usage4 (_("Set either -s/--ssl/--tls or -S/--starttls"));
+                }
         }
 
         if (server_port_option != 0) {